Inaccurate performance data for BOB fighters in COD comparing to RL data

[lane]

Originally Posted by pstyle

Here's my take on this "units concerned" business, working from most recent to oldest:

By May 18th, these "units concerned" has been stocked with the necessary 100 octane

Prior to May 18th. There are two separate lines of discussion.
One relates to Bomber command and the stocking/ holding of two fuel types a Blenheim statinos, mainly stations Wyton, Watton, Waattsiham and West Raynham.

Fighter command, on the other hand was also subject to the same "proposal" that "certain units" should "begin to use 100 octane". There was some discussion about whether or not the existing spitfires and hurricanes could actually convert to the 100 fuel without substantial modifications. However, this concern was proved unfounded. They could use the 100 fuel.

So who are these "certain units"?
Well, as Talisman identifies in his post above, these "certain units" are the "squadrons armed with fighters and Blenheims" as specified by Assistant Chief of the Air Staff - who sits ABOVE both fighter and bomber command, which is why, form the overall RAF perspective this refers to "certain units", and not ALL units.

I think it's entirely fair to suggest, that from the perspective of fighter command, this referred to ALL fighter units.

I am in agreement with Talisman that by May 18th, all of these "units concerned" were using 100 Octane. And that their Spitfires and Hurricanes could use the fuel WITHOUT considerable modification, as per the statement of Mr Tweedie, at the May 1940 meeting.

There is a sting in the tail though, while the Spits/Hurris could use the 100, they would not get the performance benefit until the modifications had occurred to each individual aircraft.

Good post pstyle. Just a thought...I'm not sure about your last statement regarding not getting the performance benefit until the modifications had occurred to each individual aircraft whilst using 100 octane. It may in fact be the case that using 100 octane without the modifications may actually have allowed for greater power than the 1310 hp provided by +12 lbs., though likely resulting in increased strain on the engine.

R.D.E.6 memo dated 14/11/39 states "The modifications to the boost control cut out to limit the maximum boost to 12 lbs. sq.in. are simple and in hand (otherwise full throttle would give about 17 lbs. sq.in.)"

See also comments of Sgt. R. C. Wilkinson, 3 Squadron, 14 May 1940

[lane]

Originally Posted by pstyle

Which "original 16"?
Who identifies these "original 16". I've not seen this bit yet (it might be too far back in the thread).. I'd happily accept a fresh link, if you'd oblige.

Assuming it were only these 16 (none of which I can find), if say, one of these 16 (as yet unidentified) squadrons was based at at a station with other units not in the 16, would that station have had both fuels?

One possibility as to which squadrons comprised the 16; at the time of the March 1939 planning memo calling for 100 octane to be brought into use by 16 squadrons, 15 squadrons were operational with Spitfires or Hurricanes, with 3 others in the process of forming or converting. The units are as follows:

Mar-39
Sqdn Base Aircraft
1 Tangmere Hurricane
19 Duxford Spitfire
32 Biggin Hill Hurricane
41 Catterick Spitfire
43 Tangmere Hurricane
46 Digby Hurricane Converting from Gauntlets March 39
54 Hornchurch Spitfire Converting from Gladiator March 39
56 North Weald Hurricane
66 Duxford Spitfire
73 Digby Hurricane
74 Hornchurch Spitfire
79 Biggin Hill Hurricane
85 Debden Hurricane
87 Debden Hurricane
111 Northolt Hurricane
151 North Weald Hurricane
213 Wittering Hurricane
501 Filton Hurricane Forming with Hurricanes in March 39

One can see from the following listing that many units had converted prior to the Battle of Britain

111 Squadron ORB 15 February 1940
151 Squadron ORB, 16 February 1940
602 Squadron ORB, 16 February 1940
611 Squadron ORB, March 1940
74 Squadron, March 1940
100 Octane Fuel - Issue of., 12th December, 1939
A.P.1590B/J.2-W, Merlin II and III--Use of +12 lb./sq.in. Boost Pressure--Alterations, 20 March 1940
Emergency +12 lbs./sq. in. Boost Operation: Pilot's Notes, Merlin II, III and IV, 4th Edition, April 1940, page 6.
Air Chief Marshal H.C.T. Dowding, Handling of Merlin in Hurricane, Spitfire and Defiant Aircraft, 1st August, 1940

56 Squadron Combat Report, 9 May 1940: twelve boost
S/L J. O. W. Oliver, 85 Squadron, 10 May 1940: pulled the plug
F/O Paul Richey, 1 Squadron, 11 May 1940: boost-override pulled
F/O E. J. Kain, 73 Squadron, 14 May 1940: pulling his boost cut out
P/O D. W. A. Stones, 79 Squadron, 14 May 1940: pulled out the emergency boost-plug
Sgt. R. C. Wilkinson, 3 Squadron, 14 May 1940: 12 P.S.I.
P/O R. P. Beamont, 87 Squadron, 15 May 1940: I pulled the tit'* for over-boost... *Emergency boost over-ride on the Merlin engine
P/O F. B. Sutton, 56 Squadron, 18 May 1940: I had to pull the tit... Emergency boost control giving extra power
F/Lt. I. R. Gleed, 87 Squadron, 18 May 1940: pull the tit *; a jerk as my supercharger goes up to twelve boosts
P/O John Bushell, 151 Squadron, 18 May 1940: I used full 12 lb boost (pulled the plug)
S/L E. M. Donaldon, 151 Sqdn., 18 May 1940: I pulled the plug and climbed at 10 lbs boost
F/O C. F. G. Adye, 17 Squadron, 18 May 1940: pulled emergency boost control
F/O C. F. G. Adye, 17 Squadron, 19 May 1940: pulled emergency boost
F/Lt. I. R. Gleed, 87 Squadron, 19 May 1940: Here goes with the tit. A jerk - the boost's shot up to twelve pounds
Sgt. L. H. B. Pearce, 79 Squadron, 20 May 1940: Pulled tit
P/O John Freeborn, 74 Squadron, 24 May 1940: boost cut-out
P/O Colin Gray (NZ), No. 54 Squadron, 25 May 1940: I pressed the emergency boost tit
P/O Colin Gray (NZ), No. 54 Squadron, 25 May 1940: +12 lbs.
P/O Al Deere, No. 54 Squadron, 26 May 1940: 12 boost
F/LT Brian Lane, 19 Squadron, 26 May 1940: automatic boost cut-out
F/LT Brian Lane, 19 Squadron, 26 May 1940: 12 lb. boost
Sgt. J. C. Harrison, 229 Squadron, 28 May 1940: I pulled the emergency boost
P/O K. B. McGlashan, 245 Squadron, 28 May 1940: We’d boost an extra four pounds, from eight to twelve
P/O C. M. Simpson, 229 Squadron, 29 May 1940: with boost out and pulled
P/O T. D. Welsh, 264 Squadron, 29 May 1940: pulled boost cut-out
F/Sgt. G. C. Unwin, 19 Squadron, 1 June 1940: 12 Boost
Sgt. P. Ottewill, 43 Squadron, 1 June 1940: automatic boost cut-out pulled
P/O M. P. Brown, 611 Squadron, 2 June 1940: opened the boost cut-out
F/O D. H. Watkins, 611 Squadron, 2 June 1940: emergency boost
F/Lt. John Webster, No. 41 Squadron, 19 June 1940: 12 lbs boost
F/Lt. R. G. Dutton, 145 Squadron, 1 July 1940: pulled the plug
609 Squadron

[Al Schlageter]

It should noted lane that the squadrons you list are doing so well before the Sept date so often stated by some.

[lane]

Originally Posted by Al Schlageter

It should noted lane that the squadrons you list are doing so well before the Sept date so often stated by some.

Yes, the historical record shows that in March 1939 when the planners were looking at converting 16 fighter squadrons to 100 octane, there were in fact only 16 operational squadrons (+/- 1) equipped with Hurricanes or Spitfires. Clearly more than 16 squadrons had converted to 100 octane before the Battle of Britain.

[ATAG_Snapper]

Originally Posted by lane

Yes, the historical record shows that in March 1939 when the planners were looking at converting 16 fighter squadrons to 100 octane, there were in fact only 16 operational squadrons (+/- 1) equipped with Hurricanes or Spitfires.

Mystery of the 16 squadrons solved.

Now the 1C devs can feel free to give our Spits and Hurries their badly-needed and much-deserved +12 lbs of overboost and resulting emergency 5 minutes or so 30 mph increase in top speed. The sooner the better - a "hotfix #2" would be just the ticket!!!!

[robtek]

I am all for it, but only if there are felt penalties for abusing/overboosting the engines of all sides longer as rated!!!

Like loosing power slowly or better a increased chance of throwing a rod or something like that, this combined with corrected oil and water temperature changes.

[fruitbat]

Originally Posted by robtek

I am all for it, but only if there are felt penalties for abusing/overboosting the engines of all sides longer as rated!!!

Like loosing power slowly or better a increased chance of throwing a rod or something like that, this combined with corrected oil and water temperature changes.

agreed.

[TomcatViP]

30MPH extra speed only ?!!!!!!!!!!!!!!

why not 300mph ?

[ATAG_Snapper]

Originally Posted by robtek

I am all for it, but only if there are felt penalties for abusing/overboosting the engines of all sides longer as rated!!!

Like loosing power slowly or better a increased chance of throwing a rod or something like that, this combined with corrected oil and water temperature changes.

+1

[ATAG_Snapper]

Originally Posted by TomcatViP

30MPH extra speed only ?!!!!!!!!!!!!!!

why not 300mph ?

http://www.il2bugtracker.com/issues/174

Where have YOU been?